1. Field of the Invention
The present invention relates to an image pickup apparatus or an image synthesizing apparatus which synthesizes a plurality of image frames produced by continuously taking images of a subject to produce a synthesized image.
2. Description of Related Art
A conventional image pickup apparatus such as a digital camera forms an optical image of a subject by means of an optical lens, and converts the optical image into an electric signal by means of an image pickup device such as a CMOS image sensor.
As a method for taking images in a dark place, there is known a method in which images of a subject are continuously taken with exposure time having smaller hand jiggle, the images are added while correcting motion of the plurality of images, thereby producing one image (e.g., see U.S. Pat. No. 7,057,645).
In the case of the patent document 1, however, a predetermined number of images are collectively continuously taken previously and then, the images are synthesized into one image. Therefore, a brightness of the synthesized image might be different from a desired by user.